.pulse {
    animation-name: pulse;
    animation-duration: 0.5s;
    animation-iteration-count: infinite;
}

@keyframes pulse{
    from {
        transform: scale3d(1,1,1);
    }
    50%{
        transform: scale3d(5,5,5);
    }
    to{
        transform: scale3d(1,1,1);
    }
}